[#1203] Move all tag definitions to mail template concern

Even the one that is mail-specific, because it is too easy to overlook
it when refactoring otherwise

app/models/concerns/mail_template_concern.rb

@@ -1,8 +1,6 @@
 module MailTemplateConcern
   extend ActiveSupport::Concern
 
-  include Rails.application.routes.url_helpers
-  include ActionView::Helpers::UrlHelper
   include TagsSubstitutionConcern
 
   def subject_for_dossier(dossier)
@@ -20,14 +18,7 @@ module MailTemplateConcern
     end
   end
 
-  private
-
   def dossier_tags
-    super + [{ libelle: 'lien dossier', description: '', lambda: -> (d) { users_dossier_recapitulatif_link(d) } }]
+    super + dossier_tags_for_mail
-  end
-
-  def users_dossier_recapitulatif_link(dossier)
-    url = users_dossier_recapitulatif_url(dossier)
-    link_to(url, url, target: '_blank')
   end
 end

app/models/concerns/tags_substitution_concern.rb

@@ -1,6 +1,9 @@
 module TagsSubstitutionConcern
   extend ActiveSupport::Concern
 
+  include Rails.application.routes.url_helpers
+  include ActionView::Helpers::UrlHelper
+
   def tags
     if procedure.for_individual?
       identity_tags = individual_tags
@@ -73,6 +76,15 @@ module TagsSubstitutionConcern
     end
   end
 
+  def dossier_tags_for_mail
+    [{ libelle: 'lien dossier', description: '', lambda: -> (d) { users_dossier_recapitulatif_link(d) } }]
+  end
+
+  def users_dossier_recapitulatif_link(dossier)
+    url = users_dossier_recapitulatif_url(dossier)
+    link_to(url, url, target: '_blank')
+  end
+
   def individual_tags
     [
       { libelle: 'civilité', description: 'M., Mme', target: :gender },